#include "btree_gist.h"
#include "btree_utils_num.h"
#include "utils/date.h"

typedef struct
{
   DateADT    lower;
   DateADT    upper;
}  dateKEY;

/*
** date ops
*/
PG_FUNCTION_INFO_V1(gbt_date_compress);
PG_FUNCTION_INFO_V1(gbt_date_union);
PG_FUNCTION_INFO_V1(gbt_date_picksplit);
PG_FUNCTION_INFO_V1(gbt_date_consistent);
PG_FUNCTION_INFO_V1(gbt_date_penalty);
PG_FUNCTION_INFO_V1(gbt_date_same);

Datum    gbt_date_compress(PG_FUNCTION_ARGS);
Datum    gbt_date_union(PG_FUNCTION_ARGS);
Datum    gbt_date_picksplit(PG_FUNCTION_ARGS);
Datum    gbt_date_consistent(PG_FUNCTION_ARGS);
Datum    gbt_date_penalty(PG_FUNCTION_ARGS);
Datum    gbt_date_same(PG_FUNCTION_ARGS);

static bool     gbt_dategt     (const void *a, const void *b)
{
  return DatumGetBool( 
     DirectFunctionCall2(date_gt,DateADTGetDatum( *((DateADT*)a) ), DateADTGetDatum( *((DateADT*)b) ) )
  );
}

static bool     gbt_datege     (const void *a, const void *b)
{
  return DatumGetBool( 
     DirectFunctionCall2(date_ge,DateADTGetDatum( *((DateADT*)a) ), DateADTGetDatum( *((DateADT*)b) ) )
  );
}

static bool     gbt_dateeq     (const void *a, const void *b)
{
  return DatumGetBool( 
     DirectFunctionCall2(date_eq,DateADTGetDatum( *((DateADT*)a) ), DateADTGetDatum( *((DateADT*)b) ) )
  );
}

static bool     gbt_datele     (const void *a, const void *b)
{
  return DatumGetBool( 
     DirectFunctionCall2(date_le,DateADTGetDatum( *((DateADT*)a) ), DateADTGetDatum( *((DateADT*)b) ) )
  );
}

static bool     gbt_datelt     (const void *a, const void *b)
{
  return DatumGetBool( 
     DirectFunctionCall2(date_lt,DateADTGetDatum( *((DateADT*)a) ), DateADTGetDatum( *((DateADT*)b) ) )
  );
}



static int
gbt_datekey_cmp(const void *a, const void *b)
{
  if ( gbt_dategt( (void*)&(((Nsrt *) a)->t[0]) , (void*)&(((Nsrt *) b)->t[0]) ) ){
    return  1;
  } else
  if ( gbt_datelt( (void*)&(((Nsrt *) a)->t[0]) , (void*)&(((Nsrt *) b)->t[0]) ) ){
    return -1;
  }
  return  0;
}


static const gbtree_ninfo tinfo = 
{
  gbt_t_date,
  sizeof(DateADT),
  gbt_dategt,
  gbt_datege,
  gbt_dateeq,
  gbt_datele,
  gbt_datelt,
  gbt_datekey_cmp
};


/**************************************************
 * date ops
 **************************************************/



Datum
gbt_date_compress(PG_FUNCTION_ARGS)
{
    GISTENTRY  *entry  = (GISTENTRY *) PG_GETARG_POINTER(0);
    GISTENTRY  *retval = NULL;
    PG_RETURN_POINTER( gbt_num_compress( retval , entry , &tinfo ));
}



Datum
gbt_date_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY        *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
    DateADT          query  = PG_GETARG_DATEADT( 1 );
    dateKEY            *kkk = (dateKEY *) DatumGetPointer(entry->key);
    GBT_NUMKEY_R        key ;
    StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
    key.lower = (GBT_NUMKEY*) &kkk->lower ;
    key.upper = (GBT_NUMKEY*) &kkk->upper ;

    PG_RETURN_BOOL(
      gbt_num_consistent( &key, (void*)&query,&strategy,GIST_LEAF(entry),&tinfo)
    );
}


Datum
gbt_date_union(PG_FUNCTION_ARGS)
{
    GistEntryVector     *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
    void                     *out = palloc(sizeof(dateKEY));
    *(int *) PG_GETARG_POINTER(1) = sizeof(dateKEY);
    PG_RETURN_POINTER( gbt_num_union ( (void*)out, entryvec, &tinfo ) );
}


Datum
gbt_date_penalty(PG_FUNCTION_ARGS)
{
        dateKEY      *origentry = (dateKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
        dateKEY      *newentry  = (dateKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(1))->key);
        float           *result = (float *)   PG_GETARG_POINTER(2);
        int32         diff, res ;

        diff = DatumGetInt32(DirectFunctionCall2(
                  date_mi,
                  DateADTGetDatum(newentry->upper),
                  DateADTGetDatum(origentry->upper)));

        res  = Max(diff, 0);

        diff = DatumGetInt32(DirectFunctionCall2(
                  date_mi,
                  DateADTGetDatum(origentry->lower),
                  DateADTGetDatum(newentry->lower)));

        res += Max(diff, 0);

        *result = 0.0;

        if ( res > 0 ){
          diff = DatumGetInt32(DirectFunctionCall2(
                  date_mi,
                  DateADTGetDatum(origentry->upper),
                  DateADTGetDatum(origentry->lower)));
          *result += FLT_MIN ;
          *result += (float) ( res / ( (double) ( res + diff ) ) );
          *result *= ( FLT_MAX / ( ( (GISTENTRY *) PG_GETARG_POINTER(0))->rel->rd_att->natts + 1 ) );
        }

        PG_RETURN_POINTER(result);
}


Datum
gbt_date_picksplit(PG_FUNCTION_ARGS)
{
  PG_RETURN_POINTER(gbt_num_picksplit(
      (GistEntryVector *) PG_GETARG_POINTER(0),
      (GIST_SPLITVEC *) PG_GETARG_POINTER(1),
      &tinfo
  ));
}

Datum
gbt_date_same(PG_FUNCTION_ARGS)
{
  dateKEY      *b1 = (dateKEY *) PG_GETARG_POINTER(0);
  dateKEY      *b2 = (dateKEY *) PG_GETARG_POINTER(1);
  bool     *result = (bool *) PG_GETARG_POINTER(2);

  *result  = gbt_num_same ( (void*)b1, (void*)b2, &tinfo );
  PG_RETURN_POINTER(result);
}
